Hammer mechanism



Dec. 26, 1967 E0. ROGGENSTEIN 3,359,892

HAMMER MECHANISM Filed Dec. 28, 1964' 3 Sheets-Sheet 1 INVENTOR EDWIN. O. ROGGENSTEI N BY AGENT Dec. 26, 1967 E. o. ROGGENSTEIN 3,359,892

HAMMER MECHANISM I5 Sheets-Sheet 2 Filed Dec. 28, 1964 INVENTOR EDWIN QROGGENSTEIN AGENT Dec. 26, 1967 HAMMER MECHANI SM 3 Sheets- Sheet 5 Filed Dec. 28, 1964 m R om S N V 7 G T W W m G A W United States Patent Gfifice 3,359,892 Patented Dec. 26, 1967 3,359,892 HAMMER MECHANISM Edwin O. Roggenstein, Birmingham, Mich., assignor to Burroughs Corporation, Detroit, Mich., a corporation of Michigan Filed Dec. 28, 1964, Ser. No. 421,193 4 Claims. (Cl. 10193) The present invention relates generally to an impacting apparatus, and more particularly relates to a hammer mechanism for use in a printing apparatus.

It is an object of this invention to provide a simple and inexpensive impacting device, such as for a printing apparatus, which possesses reliable repeatability of the energy delivered at the point of impact. Prior hammer mechanisms employed a power drive roll and shuttle cam which relied entirely on the frictional contact between the elements involved. These prior devices did not produce satisfactory repeatability of impact and were very sensitive to variations in the materials used and the tolerances obtained in the manufacturing process. These prior art disadvantages are eliminated by the present invention, because the present invention provides a positive engagement with the teeth of a power drive roll Which results in uniform powered motion of a rotatable hammer. Furthermore, the parts for the present invention are easily manufactured and maintain their adjustment over a long period of time and use.

-The present invention provides an impact mechanism comprising a power drive, a hammer, an actuator element rotatably and slidably mounted on the hammer for connecting the power drive with the hammer to impel the hammer to an impact position, and a selectively operable control'member for urging the actuator element toward the power drive.

These objects, features and advantages will become more apparent after considering the following detailed description of one possible embodiment of the present invention taken in conjunction with the accompanying drawings wherein:

FIG. 1 is an isometric drawing of the hammer mechanism shown in the initial unactuated position;

FIG. 2 shows the hammer control member urging the actuator element against the drive roll;

FIG. 3 shows the hammer mechanism in the latched position resulting after the. hammer has returned from the impact position; and p FIG. 4 is a top view of a plurality of assembled hammer mechanisms which are controllable by a single drive roll.

The hammer mechanism of the present invention may be employed as the printing device in the recording apparatus disclosed in United States Patent 3,018,721.

FIG. 1 shows a hammer I mounted for rotation on a hammer shaft 2. The hammer 1 is shown in the at' rest condition or initial unac'tuated position resting against a limit shaft 3; A single limit shaft 3 rigidly mounted in the side frames 4 and 5, shown also in FIGS. 3 and 4, is employed for a plurality of the hammers 1.

. Each hammer 1 is provided with an impact or printing element 6 which may serve, for example, to move a record member against a type element or to actuate an interposer element (not shown). The hammer 1 is provided with a limit stop 7, a limit lug 8, a stud 9, and a latching lug 10.

An actuator element 11 is associated with each of the plurality of hammers 1. The actuator element 11 is slidably, rotatably and resiliently mounted on the hammer 1. A slot 12 provided in the actuator element 11 cooperates with the stud 9 on the hammer 1 to permit sliding and rotational motion of the actuator element 11 relative to the hammer -1. A yield spring 13 interconnects the actuator element 11 with the hammer 1 and urges the actuator element 11 in a clockwise direction as shown in FIGS. 1, 2 and 3. In the unactuated position, the actuator element 11 rests against the limit stop 7 on the hammer 1, as shown in FIG. 1.

A hammer control member 14 is associated with each of the plurality of hammers 1. The control members 14 are adapted to translate within the guide bar 15. A hammer restoring spring 16 interconnects the control member 14 with its associated hammer 1 and urges the control member 14 toward the left as shown in the figures. When the bail 17 is raised and the blocking shaft 18 is moved clear of the release slide 14, the control member 14 is permitted to move toward the left under the urge of the hammer restoring spring 16.

An extension 19 on the control member 14 comes into contact with the actuator element 11, as shown in FIG. 2,

and rotates the actuator element 11 about the hammer stud 9 in a counterclockwise direction. This brings an ear 20 on the actuator element 11 into the path of the drive teeth 21, 22 and 23 provided on a continuously rotating drive roll 24. An on-coming drive tooth 21 forces the actuator element 11 downwardly causing the actuator element 11 to slide relative to the hammer 1 by means of the slot 12 and stud 9 interconnection. When the top of the slot 12 limits against the hammer stud 9, the energy which is being imparted from the drive roll 24 to, the actuator element 11 is then transmitted to the hammer 1. This causes the hammer 1 to be driven in a counterclockwise direction towards its impact position. This positive action permits the hammer 1 to be accelerated about the hammer shaft 2 under direct influence of the power drive roll 24, which remains in contact with the actuator element ear 20 for a predetermined length of time. Thus, a uniform energy level for each impacting cycle results, since the hammer 1 is positively driven toward the point of impact a predetermined number of degrees of rotation until the drive tooth 21, 22 or 23 is disengaged from the actuator element car 20. Powered motion occurs as long as a drive tooth 21, 22 or 23 remains in contact with the actuator element ear 20. p

As pressure is applied, causing the hammer 1 to accelerate toward the impact point, the actuator element .11 continues to rotate counterclockwise until it limits against the limit lug 8 (FIG. 3) integrally formed on the hammer 1. As the drive tooth 21 begins, to slide. away from the actuator element ear 20 and eventually drop off, the hammer 1 continues to rotate as described above. The yield spring 13 rotates the actuator element 11 in a clockwise direction, thereby moving it out of the path of the next on-coming drive tooth 22. The yield spring 13also restores the actuator element 11 to the initial rest position against the limit stop 7 on the hammer 1.

The purpose of the actuator element slot 12 is to provide means to permit the actuator element 11 to engage positively the teeth 21, 22 and 23 of the drive roll 24 no matter what the relationship happens to be among the hammer 1, the actuator element 11, and the drive roll 24 at the time a particular hammer control member 14 is operated. Therefore, each time the actuator element ear 20 is contacted by a drive roll tooth 21, 22 or 23, full engagement is assured even though, for example, the actuator element ear 20 collides with a drive tooth 21, 22 or 23 with only a fractional overlap of a few thousandths of an inch, Full tooth engagement repeatability is made possible through use of the yield spring 13 which can yield upon engagement before the entire load of the hammer 1 is applied to the continuously rotating drive roll 24.

In the foregoing manner, the hammer 1 is rotatably impelled to the impact position. After impact, the ham- 'rner 1 returns under the influence of gravity and the force applied by the hammer restoring spring 16. The hammer 1 tends to return to the initial unactuated position to rest against the limit shaft 3, but the hammer 1 is intercepted and latched in an intermediate position by a latching plate 25 which is provided for each of the plurality of hammers 1. The latching plate 25 is engageable with the latching lug formed on the hammer 1. Thus, once the hammer 1 has impacted in any machine cycle, it will not be able to return to its home or at rest position where it might possibly be fired or impelled for a second time during the same cycle of the machine.

Means are provided for restoring the hammers 1 to their home or at rest position against the limit shaft 3 toward the end of each cycle after the possibility of re-impacting or refiring has passed. A link 26 is secured to one arm 28 of a bell crank 27 pivoted on a shaft 30 supported by the frame 4 or 5. The shaft 30 also supports the latch plates 25 for all of the hammers 1. One end of the latch plate 25 is biased by a spring 31 tending to maintain the latch plate 25 in an upward position for engagement with the hammer lug 1i), and thereby to latch the hammer 1 in the intermediate position. The second arm 29 of the bellcrank 27 supports a shaft 32 and moves the shaft 32 whenever the link 26 is moved to the left. As will be seen, when the shaft 32 moves upwardly, it pivots all the latch plates 25 about the shaft 30 so as to disengage therefrom the lugs 10 of the hammers 1, thus permitting the hammers 1 to return to their at rest position against the limit shaft 3.

An important feature of the present invention resides in the fact that the actuator element 11 which engages the power drive roll 24 is, in effect, a part of the rotatable hammer 1 itself. It is contemplated that the stud 9 may be placed on either the hammer 1 or the actuator element 11 and that the slot 12 may be placed in the actuator element 11 or the hammer 1, respectively.

While the invention has been described with respect to a preferred embodiment thereof, it will be understood that the invention and/ or various features thereof are capable of embodiment in other forms and that many changes and variations may be made within the spirit and scope of the invention as described in the following claims.

What is claimed is:

1. A hammer mechanism comprising, in combination:

(a) a frame;

(b) drive means rotatably mounted in the frame;

(c) ahammer element rotatably mounted in the frame;

((1) an actuator element mounted on the hammer to rotate therewith;

(e) a stud formed on one of said elements cooperating with a slot formed in the other one of said elements, whereby the actuator element may slide and rotate relative to the hammer element for a predetermined limited displacement relative to said hammer element;

(f) resilient means connected between said hammer and actuator elements and urging the actuator element away from the drive means; and

(g) a control member for selectively urging the actuator element into the path of rotation of the drive means for engagement therewith, whereby the drive means moves the actuator element for said predetermined limited displacement before motion is imparted to the hammer element.

2. A hammer assembly comprising:

(a) a shaft;

(b) a hammer rotatably mounted on said shaft;

(c) an actuator element resiliently and slidably mounted on said hammer for limited motion therewith;

(d) a continuously rotating drive roll;

(e) a control member adapted to urge periodically said actuator element into the path of rotation of said drive roil;

(f) at least one projection on said drive roll;

(g) a tooth on said actuator element which is adapted to be driven by said projection on said drive roll; (h) a spring mounted on said hammer for restoring said hammer to its unactuated position;

(i) a stud integral with said hammer;

(j) a slot in said actuator element into which said stud is disposed;

(k) a spring interconnecting said actuator element and said hammer;

(l) and a limit projection on said hammer against which said actuator element rests when said actuator element is not urged into the path of said drive roll,

whereby when said actuator element is caused to move by said drive roll, the actuator element will translate relative to the hammer until prevented from further relative motion between thc actuator element and hammer by the end of said slot, whereupon further movement of said actuator element will cause the hammer to be impelled to its active position.

3. The hammer assembly as defined in claim 2, in-

cluding:

(m) a protruding element on said hammer which serves to limit the movement of said tooth on said actuator element from being further driven by the projection on said drive roll, said projection continuing in its path of rotation after slipping away from said tooth,

whereby said spring interconnecting the actuator element and hammer serves to restore said actuator element to its initial inactive position.

4. An impacting mechanism comprising:

(a) a frame;

(b) a continuously rotating drive roll mounted within the frame, the drive roll having a plurality of drive teeth equidistantly spaced-apart upon the periphery of the drive roll;

(c) a plurality of hammers rotatably mounted within the frame adjacent the drive roll, each hammer having thereon a limit lug, a stud, a limit stop, a latching lug, and an impact element;

(d) a limit shaft against which the hammers rest when in the initial unactuated positon;

(e) an actuator element havng a slot therein mounted on each hammer, the slot cooperating with the stud on the hammer to permit sliding and rotation of the actuator element to the hammer;

(f) a hammer control member for selectively rotating the actuator element toward the drive roll and the limit lug on the hammer;

(g) an ear on the actuator element which engages a drive tooth when the release slide has urged the actuator element into the path of the rotating drive roll, so that the drive tooth urges the actuator element to slide on the hammer stud until the actuator element slot limits against the hammer stud whereupon energy imparted from the drive roll to the actuator element is transmitted to the hammer causing the hammer to rotate toward its impact position;

(b) said limit lug on the hammer being engageable 5 with the actuator element to stop rotation of the actuator element relative to the hammer toward the drive roll;

(i) a spring conneced between the actuator element and the hammer urging the actuator element toward the limit stop on the hammer;

(j) a spring connected between the hammer and the control member; and

(k) a plurality of latches each associated with a corresponding hammer and adapted to engage the latching lug on the hammer when the hammer is returning from the impact position.

References Cited UNITED STATES PATENTS Fomenko et al 101-93 Malmros et al 10193 Hoffman et a1. 10193 Monticello et a1 10193 Kittler 10193 Barnes 10193 Eissfelot et al 101-93 WILLIAM B. PENN, Primary Examiner, 

1. A HAMMER MECHANISM COMPRISING, IN COMBINATION: (A) A FRAME; (B) DRIVE MEANS ROTATABLY MOUNTED IN THE FRAME; (C) A HAMMER ELEMENT ROTATABLY MOUNTED IN THE FRAME; (D) AN ACTUATOR ELEMENT MOUNTED ON THE HAMMER TO ROTATE THEREWITH; (E) A STUD FORMED ON ONE OF SAID ELEMENTS COOPERATING WITH A SLOT FORMED IN THE OTHER ONE OF SAID ELEMENTS, WHEREBY THE ACTUATOR ELEMENT MAY SLIDE AND ROTATE RELATIVE TO THE HAMMER ELEMENT FOR A PREDETERMINED LIMITED DISPLACEMENT RELATIVE TO SAID HAMMER ELEMENT; (F) RESILIENT MEANS CONNECTED BETWEEN SAID HAMMER AND ACTUATOR ELEMENTS AND URGING THE ACTUATOR ELEMENT AWAY FROM THE DRIVE MEANS; AND (G) A CONTROL MEMBER FOR SELECTIVELY URGING THE ACTUATOR ELEMENT INTO THE PATH OF ROTATION OF THE DRIVE MEANS FOR ENGAGEMENT THEREWITH, WHEREBY THE DRIVE MEANS MOVES THE ACTUATOR ELEMENT FOR SAID PREDETERMINED LIMITED DISPLACEMENT BEFORE MOTION IS IMPARTED TO THE HAMMER ELEMENT. 